• 한국염색가공학회지
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• 제24권3호
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• pp.158-164
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• 2012

Rhodamine dyes belong to xanthene family has excellent photostability and photophysical properties. In rhodamine dyes, Rhodamine 6G and its precursors also have xanthene chromophore and it shows high fluorescent quantum yield. Rhodamine 6G derivates are simple to synthesis and its high sensitivity and water solubility are suitable as good chemosensor. In this regard, Rhodamine 6G derivates which have selectivity to specific metal cation can used to detect various heavy metal ions. In this study, rhodamine 6G derivatives were synthesized by reaction of rhodamine 6G hydrazide and glyoxal and 4-phenyl thiosemicarbazide and it showed colorimetric and fluorescence sensing toward $Hg^{2+}$ ion. This novel chemosensor was analyzed and measured on UV-Vis and fluorescence spectrophotometer. HOMO/LUMO values were also calculated by computational calculation.

• 한국세라믹학회지
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• 제54권1호
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• pp.28-32
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• 2017

The degradation of methyl blue (MB) catalyzed by platinum (Pt)-graphene/$TiO_2$ in dark ambiance was studied. Pt-graphene/$TiO_2$ composites were prepared by simple hydrothermal method. Characterizations of composites were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area (BET) analysis, and energy dispersive X-ray (EDX) analysis. UV-spectroscopic analysis of the dyes was performed by measuring the change in absorbance. The degradation of the organic dyes was calculated based on the decrease in concentration of the dyes with respect to regular time intervals. Rate coefficients for the catalytic process were successfully established and reusability tests were performed to test the stability of the used catalysts.

• 한국세라믹학회지
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• 제55권3호
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• pp.239-243
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• 2018

Up to now, microstructure changes of photocatalysts have been studied to improve photocatalytic activity. Especially, to improve the adsorption of reactants and reactive sites, porous and fine crystal structures have received much attention because of their large specific surface area. In this study, $TiO_2$ nanotubes were synthesized by hydrothermal method using $TiO_2$ nanoparticles; nanotubes were evaluated by oxidized methylene blue reduction test. Using synthesized $TiO_2$ nanotubes, results of TEM showed that the $TiO_2$ nanoparticles were changed into folding sheets and nanotubes. XRD results showed that the peaks of the nanoparticles almost disappeared and only the rutile (110) and anatase (200) peaks were observed. Comparison of photocatalytic properties of nanoparticles and nanotube structures was performed by measuring the UV-vis absorbance with reducing oxidized methylene blue. As a result, the reduction rate of nanotubes was found to be $0.24{\mu}mol/s$, which was 2.6 times higher than the rate of reduction of nanoparticles.

• 대한화장품학회지
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• 제41권3호
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• pp.189-199
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• 2015

본 연구에서는 유기 자외선 흡수제와 오일들 간의 용해도에 따른 자외선 차단제의 안정성과 유기 자외선 흡수제의 조합에 따른 이들의 자외선 차단 효율 변화를 조사하여 보다 안정하고 효율이 높은 자외선 차단제품 개발에 도움이 되고자 하였다. 그 결과 오일의 종류, 농도 그리고 보관 조건에 따라서 유기 자외선 흡수제의 용해도 및 안정성이 다양하게 관찰되었으며, 이러한 현상은 에멀젼상에서도 자외선 차단지수에 영향을 나타냄을 확인하였다. 또한 유기 자외선 흡수제의 조합에 따라 다양한 자외선 흡광도가 측정되었으며, 조합 시 각각의 자체 흡광도보다 높은 시너지 효과를 나타내는 성분이 있었고, 특정 성분과의 조합 시에만 시너지 효과가 나타나는 경우도 있었다. 보관 조건에 따라서도 자외선 흡광도는 상이하게 측정되어, 자외선 차단 효율에 영향을 나타내는 다양한 변수가 있음을 확인할 수 있었다.

• 분석과학
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• 제8권2호
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• pp.117-124
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• 1995

지속적인 음주로 인하여 간경변증으로 사망한 human 간에서 ethanol에 의해서 유도되는 것으로 추측되는 hemoprotein들을 확인 및 부분정제하였다. 이 hemoprotein을 정제하기 위하여 Mohamed 등의 방법을 변형하여 단백질을 정제하였고, SDS-PAGE 및 spectrum 양상을 관찰하였다. Triton N-101을 처리한 crude extract를 준비하여 CO gas를 bubbling시킨 후 Octyl-Sepharose CL-4B column chromatography에서 0.06% Lubrol PX로 용출한 다음 0.25% Lubrol PX로 용출하였다(Fig. 2). 0.06% Lubrol PX로 용출한 active fraction을 Hydroxyapatite와 DEAE-Sephadex A-25 column으로 정제하였다(Fig. 3, 4). 정제한 단백질을 12.5% SDS-PAGE를 실시한 결과 분자량은 대조군으로 사용한 흰쥐 간에서 정제한 단백질의 분자량은 55 KDa와 52 KDa였고, 돌연사한 사람의 간에서 정제한 단백질의 분자량은 62 48KDa이며, 간경변증으로 사망한 사람의 간에서 정제한 단백질의 분자량은 54KDa였고(Fig. 5). Cytochrome P450 함량은 20.8nmol/mg protein이며 회수율은 약 4.1%이고, 이들의 최대흡수 파장은 446nm이었다(Fig. 6).

• Applied Microscopy
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• 제47권3호
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• pp.157-159
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• 2017

This study concerns (i) Botanical characterization of local almond ecotype named "Beldi" based on flowering period and flowers color measurements (ii) Chemical characterization of almond oil such as acidity and peroxide index and specific UV absorbance values (K232 & K270). The color results of 100 flowers analyzed by chromameter shows two different color categories. The first is very light pink to whitish ($L^*=81.58$, $a^*=7.43$, $b^*=8.06$). The second is a dark pink ($L^*=71.64$, $a^*=18.34$, $b^*=4.97$) with a difference in color between the two categories ${\Delta}E=15.07$. Compared to Ferragnes/Ferraduel varieties, Beldi almond kernel has almost a comparable oil yield but different acidity and peroxide values which are 0.81%, $8.12meq/O_2/kg$ and 0.40%, $16.39meq/O_2/kg$ respectively.

• Journal of Ginseng Research
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• 제9권2호
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• pp.256-263
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• 1985

In order to investigate the inferior factor of red ginseng quality, the contents of various chemical components, physico-chemical properties and arrangement state of ginseng cells were observed. Contents of total reducing sugar, reducing sugar, crude protein, crude fibre and specific gravity of inside white part of red ginseng were less than those of normal part. But differences in content of crude saponin, HPLC pattern of ginsenosides and reducing ability for DP P H(1,1-dipheny 1-2-picrylhydrazyl) between normal and inside white part of red ginseng were not found. The optical density of 1 water extract of normal part of red ginseng did not differ from that of inside white 1 part of red ginseng, but the visible and UV absorbance of acid hydrolyzate of normal red ginseng showed higher than those of inside white part of red ginseng. The differences in the internal color and tissue of normal and inside white part of red ginseng were easily found with naked eye, and by the microscopic fractography, the orangement state of ginseng cell in the inside white part of red ginseng was less dense than that in normal red ginseng.

• Ocean and Polar Research
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• 제25권4호
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• pp.427-435
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• 2003

Growth and pigment responses to different levels of solar radiation with or without ultraviolet (UV)-B component $({\lambda}=280-315nm)$ were investigated in Antarctic rhodophytes, Kallymenia antarctica and Palmaria decipiens, collected around King George Island during the summer of 2000. In K. antarctica specific growth rate, based on thallus area or fresh weight, decreased with increasing solar irradiances while P. decipiens were relatively insensitive to the effects of light. It is noticeable that the presence or absence of UV-B had no significant effect on growth for either species. However, K. antarctica showed a more pronounced reduction in chlorophyll (Chl a) concentrations at higher irradiances in the presence of UV-B. In P. decipiens, Chl a concentrations did not differ despite radiation level fluctuations being lower albeit than initial measurements. Thallus thickness was greater in K. antarctica than in P. decipiens. There were higher relative amounts of UV-absorbing pigments (UVAPs) in P. decipiens than in K, antarctica. The single absorbance peak obtained from the methanol extracts was resolved into three (316,332 and 346nm) in K. antarctica and four peaks (315,326,333 and 349 nm) in Palmaria as a result of the fourth-derivative. After 7 days exposure to solar radiation, the amount of UVAPs in K. antarctica was significantly reduced to a similar degree at all light levels, whereas that of P. decipiens remained unchanged except at 5% of surface irradiance. High performance liquid chromatography (HPLC) analysis of purified extracts indicated that P. decipiens possesses porphyra-334 in addition to three other mycosporine-like anlino acids (MAAs; asterina-330, palythine, shinorine), which are commonly present in K. antarctica. Significantly lower tolerance of K. antarctica to high levels of solar radiation may be connected with its usual absence in the eulittoral, while the active growth and elastic pigment responses of P. decipiens over a wide range of solar irradiance levels up to full sunlight seems to correspond well with its wide vertical distribution from rock pools down to 25-30m.

• 상하수도학회지
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• 제29권3호
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• pp.337-345
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• 2015

Two step rapid filter system as a pre-treatment for the injected water into aquifer storage and recovery (ASR) in Korea was developed to reduce physical blockage and secure the volume of the injected water. First, single rapid sand filters with three different media sizes (0.4~0.7, 0.7~1.0 and 1.0~1.4 mm) were tested. Only two sizes (0.4~0.7 and 0.7~1.0 mm) satisfied target turbidity, below 1.0 NTU. However, they showed the fast head loss. To prevent the fast head loss and secure the volume of the injected water, a rapid anthracite filter with roughing media size (2.0~3.4 mm) were installed before a single rapid sand filter. As results, both the target turbidity and reduction of head loss were achieved. It was determined that the media size for a rapid sand filter in two step rapid filter system (i.e. a rapid anthracite filter before a rapid sand filter) was 0.7~1.0 mm. In addition, the effects of coagulant doses on the removal of natural organic matter (NOM), which might cause a biological clogging, were preliminarily evaluated, and the values of $UV_{254}$, dissolved organic carbon (DOC) and SUVA were interpreted.

• 환경생물
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• 제34권1호
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• pp.48-55
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• 2016

본 연구는 자외선 광분해에 의한 비스페놀 A (BPA)의 에스트로겐 활성 저감에 미치는 하수처리장 방류수 유기물질의 영향을 조사하였다. 방류수 유기물질과 표준으로 사용한 스와니강 자연 유기물질은 극성에 따라 소수성, 반친수성, 친수성 분획으로 분리하였다. 특이 자외선 흡수 (SUVA) 분석 결과, 방류수 유기물질은 높는 소수성을 가지고 있는 자연 유기물질과 다르게 소수성이 낮은 미생물 기원 유기물질과 유사한 특성을 나타내었다. 3시간의 자외선 조사는 방류수 및 자연 유기물질의 극성에 따라 SUVA 값을 유의하게 감소시켰다 (p<0.0001). 유기물질이 없는 조건에서, BPA($5.0{\times}10^{-5}M$)의 상대 에스트로겐 활성도는 자외선 광분해에 의해 86%에서 63%로 감소하였다. 그러나 유기물질이 있는 조건에서 상대 에스트로겐 활성도는 평균적으로 68%에서 37%로 감소하였으며, 유기물질의 종류 (방류수 또는 자연유기물질) 및 극성 (소수성, 반친수성, 친수성)과 유의한 차이를 나타내지 않았다 (p>0.05). 결과적으로, 유기물질이 있고 없는 조건에서 자외선 광분해에 의해 감소한 BPA의 상대 에스트로겐 활성도는 각각 31%와 23%였으며, 이것은 방류수와 자연 유기물질 모두 광분해에 의한 BPA의 에스트로겐 활성 저감을 촉진시킨다는 것을 제시한다.